Eclipse Web Tools Frequent Asked Questions

Many of the FAQ's found on this page have been pulled from the WTP newsgroup. Thank you to everyone that took the time to answer these questions.

Looking for FAQ's related to the development of WTP? See the Committer FAQ.

If you have identified a FAQ that is not in this list, please add it to the list. You will need a bugzilla user id in order to edit the page.

General

How is the Eclipse Web Tools Platform licensed?

The Eclipse Web Tools Platform (WTP) consists of software produced by the Eclipse Project combined with third party software from other open source projects. The software produced by the Eclipse Project is made available under the Eclipse Public License. Third party components are made available under their own licenses. The detailed licensing information can be found in the Eclipse.org Software User Agreement (notice.html) file in the root directory of the SDK download. Licensing for third party components is described in about.html files in the respective subdirectories.

How can I tell what is new and noteworthy within an specific release?

All of the New and Noteworthy documents can be found on the main web site. A new set of documents is usually prepared for each Milestone and collected together for each Release.

How can I find a list of known problems with a release?

While there may be specific Release Notes added for the latest release, what is in Bugzilla is generally regarded as complete. Remember: if you don't file your bug reports, no one will have a chance to fix them.

Why am I getting a java.lang.OutOfMemoryError: PermGen space?

The default maximum Permanent Generation space set by your JRE may be too small. This is unrelated to the maximum allowed Heap space. You can increase the maximum PermGen size by launching Eclipse with the VM argument: -XX:MaxPermSize=128m

Note that this issue only appears to happen using a Sun/Oracle Java Runtime. Others runtime environments do not seem to have this issue, or may themselves use different methods to control their maximum allowed PermGen size.

Who are the contributors to the Eclipse Web Tools Platform Project?

We have a whole page listing the hard working contributors to this project. See the Committer FAQ if you are a committer.

What version of Eclipse does WTP work with?

WTP 1.0.x runs on Eclipse 3.1.x.

WTP 1.5.x runs on Eclipse 3.2 (a.k.a. Callisto).

WTP 2.0.x runs on Eclipse 3.3 (a.k.a. Europa).

WTP 3.0.x runs on Eclipse 3.4 (a.k.a. Ganymede).

WTP 3.1 runs on Eclipse 3.5 (a.k.a. Galileo).

WTP 3.2 runs on Eclipse 3.6 (a.k.a. Helios).

WTP 3.3 plans to run on Eclipse 3.7/4.1.

Which zip file should I download?

The WTP SDK (wtp-sdk-*.zip) includes everything produced by the WTP project, including source and both user and programmer documentation. If you aren't sure which download you need, you should probably get the WTP-SDK.

The software development kit (SDK) downloads are for developers wishing to build solutions on top of the Web Tools Platform, while the non-SDK downloads are suitable for everyone else's use. The project also provides various other builds for easier use by other projects and adopters.

How do I install WTP?

The Web Tools Platform has several required projects that must all be installed for proper operation. Each WTP build is built and tested with specific versions of these prerequisites (see the Requirements section on each specific build's download page) and it is recommended that only those versions be installed and active when used with a particular WTP build. The WTP download page for each build details the complete list of requirements and provides links to download the corresponding versions. Downloading and unpacking each should place its contents into a folder named eclipse.

How do I include Java classpath entries in a Java EE project's published/exported module structure?

Server/Internet

Where are cached files located?

The cached files are located in WORKSPACE_DIR/.metadata/.plugins/org.eclipse.wst.internet.cache. The entries are all named with numbers but you can see the mappings in the cache.xml file located in the same directory.

How do I debug JSPs with BEA WebLogic Server 8.x?

BEA WebLogic Server 8.x and earlier do not support JSR-45; WebLogic Server 9.x and later do support JSR-45 so you can debug JSP files with them using WTP (note: there are outstanding issues with JSP source lookup for the WLS Generic adapter in 0.7 - see bug 104401).

How do I debug JSPs with Apache Tomcat 4.x?

Apache Tomcat 4.x and earlier do not support JSR-45; Tomcat 5.x and later do support JSR-45 so you can debug JSP files with them using WTP.

Where can I find out more about the Tomcat support in WTP?

For more information about the support for Tomcat 4.0 through Tomcat 7 in WTP, see this separate WTP_Tomcat_FAQ.

Web

Why does the HTML editor show a validation error if I don't use closing </p> or </br> tags?

You're likely editing an XHTML file which requires that the file be well formed XML.

Does WTP's JavaScript editor report syntax errors?

Yes, the JavaScript Development Tools (JSDT) available in WTP 3.0 and newer provides a Validator. For projects that are not already JavaScript projects, use the project's Configure context menu to make it a JavaScript project. For JavaScript in web pages, you will need the Validation Builder installed on a project as well (check the project Properties dialog).

Web Services

Can the WSDL validator be extended to validate extension elements, for example partnerLinks and properties from the WS-BPEL specification?

Yes! The WSDL validator has extension points (which should all be considered internal, non-API at this point) which allow you to plug your own extension validator for a given namespace into the WSDL validator.

In this case, you can create a validator for the WS-BPEL namespace and plug-it into the WSDL validator. Your validator will get called any time an element from the WS-BPEL namespace is encountered.

The WSDL HTTP validator and SOAP validator both use this extension mechanism. To contribute your validator to the WSDL validator you need to specify an entry in your plugin manifest as follows:
(I'm assuming http://schemas.xmlsoap.org/ws/2004/03/business-process/ is the BPEL namespace.)

184627 - Error deleting Axis2 project. The workaround is to stop the server first and then remove the project from the server before deleting the project.

XML

How do I use my own filename extensions in the XML editor? It only works correctly if a file ends with .xml.

Note: this also applies to the JSP and HTML editors and others in WTP

Earlier versions of Eclipse only allowed users to associated editors with custom file names using the File Associations preference page. Eclipse 3.1 and newer support a more flexible notion of Content Types that allows more than just editors to treat custom-named files as XML, for example. Instead of using the File Associations preference page, add the filename extension to the new Content Types preference page. Doing so "teaches" Eclipse about that filename extension so that features such as Validation and Task Tag detection also support those files correctly.

How do I programmatically add entries to the XML catalog?

The XML catalog extension point schema contains specific definitions of how to use the extension point. You can view the schema here.

For easier viewing, checkout the org.eclipse.wst.xml.core plugin from the repository and view this file with the Eclipse extension schema editor.

Why does the XML catalog preference dialog only show URI Key type entry when no file is selected?

As Public ID and System ID are only applicable to DTD entity resolution in order to see these options in addition to URI for the Key Type choice you must first select a DTD file.

When you select an XSD file you will see Namespace Name and Schema Location for the Key Type selection.